The present invention relates to exercise methods and apparatus and more particularly, to unique linkage arrangements between arm driven members and leg driven members which are suitable for use on elliptical exercise machines and other types of exercise equipment.
Exercise equipment has been designed to facilitate a variety of exercise motions, many of which incorporate both arm and leg movements. Examples of such equipment include elliptical exercise machines (e.g., see U.S. Pat. Nos. 5,242,343, 5,423,729, 5,540,637, 5,725,457, and 5,792,026); free form exercise machines (e.g., see U.S. Pat. No. 5,290,211); rider exercise machines (e.g., see U.S. Pat. Nos. 2,603,486, 5,695,434, 5,997,446); glider/strider exercise machines (e.g., see U.S. Pat. Nos. 4,940,233, 5,795,268); stepper exercise machines (e.g., see U.S. Pat. No. 4,934,690); bicycle exercise machines (e.g., see U.S. Pat. Nos. 4,188,030, 4,509,742); and other, miscellaneous exercise machines (e.g., see U.S. Pat. Nos. 4,869,494, 5,039,088). These patents are incorporated herein by reference to show suitable applications for the present invention.
On many such exercise machines, arm driven members and leg driven members are synchronized to facilitate a coordinated xe2x80x9ctotal bodyxe2x80x9d exercise motion. The synchronized motion is considered advantageous to the extent that it makes the equipment relatively easy to use. On the other hand, the perceived quality of exercise tends to exceed the actual quality of the exercise because the arms typically perform very little work. In industry terminology, the arms are just along for the ride.
In contrast to the foregoing machines, other exercise machines have been developed to provide independent upper body exercise and lower body exercise. One such machine is the NordicTrack ski machine (as shown in U.S. Pat. No. 4,728,102). On machines of this type, both the perceived quality of exercise and the actual quality of exercise are relatively more strenuous. The unfortunate trade-off is that many people consider ski machines relatively difficult to use, due to the independent arm and leg motions.
As compared to the ski machines and other machines with independent motion, another shortcoming of the xe2x80x9csynchronizedxe2x80x9d machines is that the handles are often constrained to move back and forth regardless of whether or not the user wishes to move his arms while moving his legs. In such cases, the arms can be a nuisance and/or a potential source of injury. One known solution to this problem is to alternatively pin the arms to respective leg driven members or the frame (as shown in U.S. Pat. No. 5,792,026). This approach leaves room for improvement to the extent that the exercise activity must stop in order to accommodate insertion of the pins, and/or there is a transition interval wherein the position of the arms is not dictated by either the leg driven members or the frame. In this regard, the U.S. Pat. No. 5,792,026 patent teaches that the arms may be exercised independent of the legs when the pins are entirely removed. However, this alternative mode of operation simply brings users back to the difficulties often associated with the ski machines (uncoordinated arm and leg movements), and it does not address the requirement that exercise activity cease in order to change modes. Recognizing that each of the foregoing types of total body exercise machines suffer certain shortcomings, room for improvement remains with respect to total body exercise machines.
The present invention provides unique methods and apparatus for linking a leg driven member and an arm driven member. The present invention may be implemented in various ways to achieve various results. For example, the present invention may be described in terms of constraining an arm driven member to be both (a) synchronized relative to a leg driven member and (b) movable through a variable range of motion while the leg driven member moves through a prescribed range of motion. The present invention may also be described in terms of constraining an arm driven member to be both (a) synchronized relative to a leg driven member and (b) selectively movable (or selectively xe2x80x9cstoppablexe2x80x9d) at any time. The present invention may also be described in terms of constraining an arm driven member to be both (a) synchronized relative to a leg driven member and (b) subjected to resistance independent of the leg driven member. The present invention may also be described in terms of the position of the arm driven member being (a) alternatively determined by the frame and the leg member and (b) always determined by one or the other.
A preferred embodiment of the present invention generally includes a frame; a leg driven member; an arm driven member; and a transmission assembly. At least one of the leg driven member and the arm driven member is pivotally connected to the frame. The preferred embodiment transmission assembly includes a plurality of links interconnected between the leg driven member and the arm driven member in a manner which provides all of the attributes described in the preceding paragraph. More specifically, first and second links are pivotally connected to one another and pivotally interconnected between the leg driven member and the arm driven member in a manner which constrains the leg driven member and the arm driven member to pivot together in a common rotational direction. The range of motion of the arm driven member is a function of a distance between the pivot axis of the leg driven member and the pivot axis defined between the first and second links. Third and fourth links are pivotally connected to one another and pivotally interconnected between the frame and one of the first and second links. The third and fourth links facilitate adjustment of the pivot axis defined between the first and second links relative to the pivot axis of the leg driven member.
Certain additional benefits may be realized by connecting both a resistance device and a dampening device to at least one of the third and fourth links. Still other benefits may be realized by connecting a powered actuator to at least one of the third and fourth links.
The preferred embodiment of the present invention is described in greater detail below with reference to the accompanying figures. The preferred embodiment is considered advantageous because it requires simple mechanical parts, is relatively compact, and is relatively easy to incorporate into existing exercise equipment. However, the present invention is not limited to this particular embodiment, nor to the type of machine on which it is shown. Moreover, the present invention is applicable to different combinations of force receiving and/or limb moving members. Additional variations and/or advantages may become more apparent from the detailed description that follows.